#12657: GHC and GHCi: RWX mmap denied by GrSec, results in a segfault -------------------------------------+------------------------------------- Reporter: PoroCYon | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 8.0.1 Resolution: | Keywords: grsec, pax, | mmap, rts Operating System: Linux | Architecture: x86_64 | (amd64) Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by pumpkin): Replying to [comment:6 simonmar]:
The linker should mmap RW during linking and them remap RX when linking is complete. I think the new m32 allocator will make things a more difficult though, because it maintains partial pages of linked code, and we can't remap one of those pages from RX to RW since it might already be in use.
I think grsecurity tracks writability history as well, so it forbids a page from being executable that was ever writable (by a given process) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12657#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler